The man was identified as DeWayne Craddock, 40, according to a law enforcement official and a Virginia government source. He walked into the city building Friday afternoon and opened fire, killing a dozen people and wounding four others, police said.

Four officers who responded to the scene followed the sound of his gunshots and engaged him in a "long gunbattle," police Chief James Cervera said. He suffered injuries during a gunfight with officers and died shortly afterward, Cervera said.

Authorities are still investigating a motive.

Gunman worked on road projects

Craddock, 40, was a certified professional engineer for the city of Virginia Beach in the public utilities department. He is listed on department news releases as a point of contact for information on local road projects over the past several years.

Craddock's parents, reached by phone Friday evening, told CNN that they weren't aware their son had been involved in the shooting and that law enforcement hadn't contacted them.

They confirmed their son worked for Virginia Beach's public works department but said they weren't aware of any trouble he was having with this employer.

A search of online court records in Virginia Beach and surrounding counties shows Craddock was cited for a motor vehicle infraction in 2013 but nothing else.

According to a 1996 news report, he served in the Army National Guard as a private after attending a high school in Newport News.

He kept to himself, neighbor says

A neighbor of Craddock's told CNN affiliate WAVY that the gunman kept to himself and was always in and out of his apartment with a book bag.

Cassetty Howerin, 23, lived below Craddock and said he was awake during all hours of the night.

"You heard him walking around; he would drop stuff at like 2 a.m., and me and my roommate would try to figure out what he was doing," Howerin said.

His neighbors said they rarely saw him.

He didn't engage in much talk, Howerin said, adding "in the year I've been there, we've maybe had three conversations and that's about it."

"I know what gym he goes to. That's about it."

He would just go in and out, the neighbor said. By the time Howerin would wake up and leave at 7 a.m., he was gone.

"I never saw him take trash out, never saw him bring groceries in, never saw people coming in or out," the neighbor said. "He was very to himself."

Howerin said they are petrified. "I live right under him, so that could have easily been me or my girlfriend or my roommate," Howerin said.

Despite their few conversations, he "seemed like a nice guy," Howerin said. "He introduced himself when we first moved in. That's just crazy."

Craddock looked like a "jacked guy, he stood maybe 6 foot and he always carried a book bag with him. That's all I really know," Howerin said.